/**
 * @file softplusv2_custom.cpp
 *
 * Copyright (C) 2024. Huawei Technologies Co., Ltd. All rights reserved.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */
#include "kernel_operator.h"

constexpr int32_t TOTAL_LENGTH = 8 * 2048;
constexpr int32_t USE_CORE_NUM = 8;
constexpr int32_t BLOCK_LENGTH = TOTAL_LENGTH / USE_CORE_NUM;
constexpr int32_t TILE_NUM = 8;
constexpr int32_t BUFFER_NUM = 2;
constexpr int32_t TILE_LENGTH = BLOCK_LENGTH / TILE_NUM / BUFFER_NUM;

class KernelSoftPlusV2 {
public:
    __aicore__ inline KernelSoftPlusV2() {}

    __aicore__ inline void Init(GM_ADDR x, GM_ADDR z)
    {
        xGm.SetGlobalBuffer((__gm__ half *)x + BLOCK_LENGTH * AscendC::GetBlockIdx(), BLOCK_LENGTH);
        zGm.SetGlobalBuffer((__gm__ half *)z + BLOCK_LENGTH * AscendC::GetBlockIdx(), BLOCK_LENGTH);
        pipe.InitBuffer(inQueueX, BUFFER_NUM, TILE_LENGTH * sizeof(half));
        pipe.InitBuffer(outQueueZ, BUFFER_NUM, TILE_LENGTH * sizeof(half));
    }

    __aicore__ inline void Process()
    {
        int32_t loopCount = TILE_NUM * BUFFER_NUM;
        for (int32_t i = 0; i < loopCount; ++i) {
            CopyIn(i);
            Compute(i);
            CopyOut(i);
        }
    }

private:
    __aicore__ inline void CopyIn(int32_t progress)
    {
        AscendC::LocalTensor<half> xLocal = inQueueX.AllocTensor<half>();
        AscendC::DataCopy(xLocal, xGm[progress * TILE_LENGTH], TILE_LENGTH);
        inQueueX.EnQue(xLocal);
    }

    __aicore__ inline void Compute(int32_t progress)
    {
        AscendC::LocalTensor<half> xLocal = inQueueX.DeQue<half>();
        AscendC::LocalTensor<half> yLocal = outQueueZ.AllocTensor<half>();
        AscendC::LocalTensor<half> tmpLocal = inQueueX.AllocTensor<half>();

        // Step 1: tmp = exp(x)
        AscendC::Exp(tmpLocal, xLocal, TILE_LENGTH);

        // Step 2: y = 1.0
        for (int i = 0; i < TILE_LENGTH; ++i) {
            yLocal.SetValue(i, static_cast<half>(1.0f));
        }

        // Step 3: tmp = exp(x) + 1
        AscendC::Add(tmpLocal, tmpLocal, yLocal, TILE_LENGTH);

        // Step 4: y = ln(exp(x)+1)
        AscendC::Ln(yLocal, tmpLocal, TILE_LENGTH);

        outQueueZ.EnQue<half>(yLocal);
        inQueueX.FreeTensor(xLocal);
        inQueueX.FreeTensor(tmpLocal);
    }

    __aicore__ inline void CopyOut(int32_t progress)
    {
        AscendC::LocalTensor<half> zLocal = outQueueZ.DeQue<half>();
        AscendC::DataCopy(zGm[progress * TILE_LENGTH], zLocal, TILE_LENGTH);
        outQueueZ.FreeTensor(zLocal);
    }

private:
    AscendC::TPipe pipe;
    AscendC::TQue<AscendC::TPosition::VECIN, BUFFER_NUM> inQueueX;
    AscendC::TQue<AscendC::TPosition::VECOUT, BUFFER_NUM> outQueueZ;
    AscendC::GlobalTensor<half> xGm;
    AscendC::GlobalTensor<half> zGm;
};

extern "C" __global__ __aicore__ void softplusv2_custom(GM_ADDR x, GM_ADDR z)
{
    KernelSoftPlusV2 op;
    op.Init(x, z);
    op.Process();
}

#ifndef ASCENDC_CPU_DEBUG
void softplusv2_custom_do(uint32_t blockDim, void *stream, uint8_t *x, uint8_t *z)
{
    softplusv2_custom<<<blockDim, nullptr, stream>>>(x, z);
}
#endif
